I think JS is the best salesperson for BW. They should recruit you to be their ambassador! Very informative and lots of beautiful pictures. Everyone saw them would like to go.
In terms of the weather I was there during their last week a couple of years ago - the last week of March going into April . The weather was perfect. The snow was plenty. Everyday is sunshine. I think snowboarders would particularly like BW.
If you like steep go to Silver Star - only 2 hours away from Big White but that is a real skier's mountain. You will like the challenge and the variety.